Can anyone tell me where the SECU is located on a 2005 Quest and what it might look like? My interior lights aren't working and someone on another Nissan forum told me it might be a bad SECU or connection to the SECU. I've already checked the fuses multiple times and they all look good.

i'm linking that other site, unless a mod tells me that its against the rules so we can be on the same page:

http://x.nissanhelp.com/forums/quest/16 ... ights.html

"... it all seems to point to something called the BCM (body control module). Is this the same thing? Am I barking up the wrong tree here?"

I'm looking at the same FSM from this site as well; i think you're in the right track!

but with the pics, it seems you'll have to remove the dashboard to see it buried under the driver side

and from that other site, you already made sure that the fuses for the BCM are good & the lamps on demand switch is set for door on?

FSM testing procedures starts on page LT-145 & you'll need access to the BCM's connectors to jamb some testing probes of the multimeter to check for power and ground circuits... good luck; i suck at electrical
http://www.nicoclub.com/FSM/quest/2005_Quest/lt.pdf

did more digging, guess they RENAMED it from Smart Entrance Control Unit for quest models up to the year 2002... when Nissan severed their joint venture with Ford/ Mercury... it is now CHANGED to Body Control Module

compare the schematics from your year FSM to my year FSM:

http://www.nicoclub.com/FSM/quest/2002_Quest/el.pdf

scroll to page EL-266 on my model and see the same exact thing on your 2005 FSM~

Great! Good to know I'm looking at the right place. I just got back from vacation last night and I hope to get a look at the BCM this weekend.